Automated Meter Reading (AMR) was developed as a more efficient and accurate method for utility meter data collection, as compared to prior manual meter reading of electric, gas and water meters, and several important advantages of AMR over manual meter reading helped develop it into a specialized branch of the data communications and telemetry industry. Worth noting among these advantages are the reliability, accuracy and regular availability of such metering data, which may be collected from hard-to-reach meter locations as well as from standard meter locations; higher customer security (no need to enter homes) and satisfaction (accurate bills); and reduced cost of customer service call center and service house calls for settling billing disputes.
Various technologies have been used in previous AMR systems to perform the tasks of interfacing the meter in order to sense consumption, communicating consumption data to a central site, and storing consumption data in a computer system at the central site. Wireless technologies, which have become the most common in AMR system implementation due to the ease of the installation process and, in many cases, the low initial and operating costs of the system, include both mobile data collection systems and fixed-base data collection systems, or networks. Although both provide a more reliable method of collecting monthly meter reads for billing purposes, fixed networks have some distinct, and important, advantages, brought about by the capability of such systems to provide frequent (typically at least daily) consumption data collection, which is difficult to do with typical mobile systems. Other advantages include: flexibility of billing date; marketing tools such as time-of-use (TOU) rates, demand analysis and load profiling, which enable clearer market segmentation and more accurate forecasts for utility resource generation, and also serve the goal of energy conservation and efficient consumption; and maintenance tools such as immediate notification of utility resource leakage or of account delinquency. These advantages have triggered increased interest and commercial activity regarding fixed network data collection systems for utilities, particularly utilities in regions undergoing deregulation of utility services.
Several methods and systems for implementing fixed-base data collection from a plurality of remote devices, such as utility meters, to a central location, have been developed and introduced in the past years. A categorization has evolved within the AMR industry, generally differentiating between one-way and two-way wireless data networks. Some systems require that each meter module on the network be a two-way module, i.e. contain a receiver circuit in the meter module. Although two-way communication features such as on-demand meter reading and other remote commands for meter configuration and control are generally desirable, they may not be required for the entire meter population of a utility. Since the inclusion of a receiver in the meter module contributes significant cost to the module, it would be most desirable to allow a utility service company the flexibility to deploy an AMR network which may contain and support both one-way and two-way meter modules.
One-way (collection only) data networks can support the large volume of data expected with the use of advanced metering applications, as by deploying intermediate data collection nodes, each of which creates a small data collection cell with a short-range RF link and a typical service population of several hundreds of meters. In such networks, the intermediate data collection nodes receive messages from meter modules, perform metering data analysis, and extract, or generate, specific meter function values to be transmitted to the next level in the network hierarchy. A wide-area network (WAN) may be provided to connect the intermediate level to the higher level. This configuration, which distributes the ‘network intelligence’ among many data collection nodes, serves the purpose of reducing the data flow into the central database when a large number of meters are analyzed for load profile or interval consumption data. It also serves the purpose of reducing air-message traffic between the intermediate node and the higher-level concentrator node. However, this configuration becomes inefficient in the common case where only a part, or even none, of the meter population requires advanced metering services like time-of-use (TOU) rates, while basic daily metering service is required for the whole meter population. This inefficiency is imposed by the short-range radio link between the meters and the data collection nodes, which significantly limits the number of meters a node can serve, regardless of how many meters need to be read frequently for interval consumption data. In this case, an expensive infrastructure of up to thousands of data collection nodes may be deployed, which often results in a great deal of unused excess capacity. A more efficient network would therefore be desirable, in order to reduce basic equipment cost, as well as to reduce installation and ongoing maintenance costs.
Another inefficiency arises due to the fact that with a large number of data collection nodes, the most cost-efficient wide area network (WAN) layer in these multi-tier networks would be a wireless WAN. However, to avoid interference from meter modules, as well as to avoid over-complication of the data protocols, an additional, licensed frequency channel is typically used for the WAN, adding to the overall cost of services to the network operator. A network composed of only one wireless data collection layer would therefore be desirable, particularly if operating in the unlicensed Industrial, Scientific and Medical (ISM) band.
Yet another disadvantage of networks with distributed intelligence among data collection nodes is the limited storage and processing power of these nodes. A system that could efficiently transfer all the raw data from the meter modules to the network's central database would therefore be desirable, since it would allow for more backup and archiving options and also for more complex function calculations on the raw meter data.
Another prior data collection network includes only a few reception sites, each one capable of handling up to tens of thousands of meters. In order to obtain long communication range, meter module antennas must be installed in a separate (higher and/or out of building) location from the meter module, and wiring must be added between the meter module and the antenna, creating significant additional cost to the meter module installation, and significantly reducing the commercial feasibility for practical deployment of the network.
None of the above-mentioned systems of the prior art offers a level of flexibility that will enable a network operator to deploy a reliable, low cost, fixed data collection network, which will meet a wide range of AMR application requirements, from basic daily meter reads to full two-way capabilities. Inefficiencies exist in the prior two-way networks, in which the two-way capability is imposed on the entire meter population, and also in the prior one-way networks, in which small cell configuration requires a large, unnecessary investment in infrastructure.
It is therefore desirable to introduce a simple to deploy, but highly scalable, modular, and reliable data collection system, which would offer a wide range of service options, from basic metering, to advanced applications based on interval consumption data, to full two-way applications, while keeping the system's deployment and ongoing costs proportional to the service options and capacity requirements selected for various segments of the meter population.